1. Technical Field
The present invention relates to a compound for an organic light-emitting diode (OLED), an OLED, and an organic light-emitting apparatus.
2. Description of the Related Art
Organic light-emitting diodes (OLEDs) are self-emission diodes that have wide viewing angles, high contrast ratios, short response times, and good brightness, driving voltage, and response speed characteristics. Also, OLEDs are capable of generating multi-color images.
In a typical OLED, an anode is formed on a substrate, and a hole transport layer, emission layer, electron transport layer, and cathode are sequentially formed (in that order) on the anode. In this regard, the hole transport layer, the emission layer, and the electron transport layer are organic thin layers that include organic compounds.
The operating principle of an OLED having the above structure will now be described. Holes injected from the anode pass through the hole transport layer and migrate toward the emission layer, and electrons injected from the cathode pass through the electron transport layer and migrate toward the emission layer. Carriers, such as the holes and electrons, are recombined in the emission layer to generate excitons, and then the excitons change from an excited state to a ground state, thereby generating light.